1. Field of the Invention
The present invention relates to an antenna for a magnetic resonance device of the type having a first antenna conductor structure with two opposite end regions, with respective electrical connections arranged at these end regions.
2. Description of the Prior Art
U.S. Pat. No. 4,825,163 discloses an antenna of the above type. The antenna has four longitudinal conductors arranged longitudinally on a cylinder cladding surface, these conductors all being connected via annular conductors at the ends. Two opposing longitudinal conductors respectively form a linear system with its own signal terminal. Such an antenna is often utilized exclusively as a reception antenna. The excitation of the nuclear magnetic resonance then occurs by means of a whole-body antenna which has a homogeneous field distribution. The reception antenna is inactive during the transmission process of the whole-body antenna.
U.S. Pat. No. 5,382,903 describes an antenna which has a narrowly limited field of view and thus can emit signals with a low noise level. This antenna has an antenna conductor structure with two conductor loops of equal size which are essentially adjacently arranged on one surface, and the conductor loops are serially connected to a junction with opposite polarity. The signal connection for each connection pair occurs via a capacitor which is inserted in one of the conductor loops. The antenna further has annular conductor loops oriented perpendicularly to the antenna conductor structure, this antenna conductor structure suppressing undesirable signals.
U.S. Pat. No. 5,435,302 teaches a flexible surface antenna having a crossed antenna conductor structure with two adjacently arranged conductor loops connected in series with opposite polarity, as also used in the antenna described in the previously cited U.S. Pat. No. 5,382,903.
If the abovementioned antenna is used as reception antenna only, then visible shadows appear in the NMR tomogram in the region of the band-shaped longitudinal conductors of the antenna.